Persons engaging in business in New Mexico must register with TRD. With few exceptions, a business must hold a Combined Reporting System (CRS) identification number, also known as a state tax identification number. CRS is TRD’s method for reporting the state’s major business taxes: gross receipts tax, all local option gross receipts taxes, compensating tax, and withholding tax. For more information, click FYI-102 Information for New Businesses.